IPCC Report Blames Extreme Weather on Climate Change...But Should It?

An international panel of climate scientists is blaming global warming on the relatively recent severe storms, droughts and heat waves. Not only that but it is stating nations should prepare for an unprecedented onslaught of more deadly and costly weather disasters.

The 594-page report by the Intergovernmental Panel on Climate Change says the scale of recent and future disasters are a combination of man-made climate change, population shifts and poverty. But are these factors really to blame for the weather? NASA explains that there is a difference between weather and climate -- that difference is a measure of time:

Weather is what conditions of the atmosphere are over a short period of time, and climate is how the atmosphere "behaves" over relatively long periods of time.

When we talk about climate change, we talk about changes in long-term averages of daily weather.

The example of between weather and climate change provided by NASA is a parent describing the big snow storms of yesteryear (this would be weather) are not as severe as those experienced by their children. This "change in recent winter snow [would] indicate that the climate has changed since their parents were young." Climate scientists themselves note the difference between recent weather events and climate.

In the past, the Intergovernmental Panel on Climate Change, founded in 1988 by the United Nations, has focused on the slow inexorable rise of temperatures and oceans as part of global warming. But this report by the panel is the first to look at the less common but more noticeable extreme weather changes, which recently have been costing on average about $80 billion a year in damage.

"We mostly experience weather and climate through the extreme," said Stanford University climate scientist Chris Field, who is one of the report's top editors. "That's where we have the losses. That's where we have the insurance payments. That's where things have the potential to fall apart."

(Related: New poll claims belief in global warming is rising, but that's not the whole story)

The scientists are citing certain places as more at risk for extreme, damaging weather. They state parts Mumbai in India, could become uninhabitable from floods, storms and rising seas. Other cities at lesser risk include Miami, Shanghai, Bangkok, China's Guangzhou, Vietnam's Ho Chi Minh City, Myanmar's Yangon (formerly known as Rangoon) and India's Kolkata (formerly known as Calcutta). The people of small island nations, such as the Maldives, may also need to abandon their homes because of rising seas and fierce storms.

Field pointed to storm-and-flood-prone Bangladesh, an impoverished country that has learned from its past disasters. In 1970, a Category 3 tropical cyclone named Bhola killed more than 300,000 people. In 2007, a stronger cyclone killed only 4,200 people. Despite the loss of life, the country is considered a success story because it was better prepared and invested in warning and disaster prevention, Field said.

Yet, the report seems to contradict some of these warnings with low to moderate confidence levels in the observed changes in some of these weather events:

• There is low confidence in any observed long-term (i.e., 40 years or more) increases in tropical cyclone activity.
• There is low confidence in observed trends in small spatial-scale phenomena such as tornadoes and hail because of data inhomogeneities and inadequacies in monitoring systems.
• There is medium confidence that some regions of the world have experienced more intense and longer droughts, in particular in southern Europe and West Africa, but in some regions droughts have become less frequent, less intense, or shorter
• There is limited to medium evidence available to assess climate-driven observed changes in the magnitude and frequency of floods at regional scales because the available instrumental records of floods at gauge stations are limited in space and time, and because of confounding effects of changes in land use and engineering. Furthermore, there is low agreement in this evidence, and thus overall low confidence at the global scale regarding even the sign of these changes.

When the summary report was released in November 2011, James Taylor in Forbes called these "scientific gaps regarding asserted connections between global warming and extreme weather events." At that same time, chairman of the IPCC Dr. Rajendra Pachauri told the Guardian that he expected strong denial over the link between climate change and recent extreme weather events: "As we said in the 2007 assessment report," he told me, "floods, droughts, and heatwaves will all increase. We abide by that, and we hope the world accepts it. We can never link a specific event, but the aggregate analysis is totally sound."

Here's a video report from IPCC of the report:

The Associated Press contributed to this report.